Leading climate scientists are advising governments and the livestock industry to reject an “accounting trick” that could undermine efforts to control heat-trapping emissions.
The group of 42 scientists has urged Ireland, a major dairy producer, to reject a proposal allowing the use of Global Warming Potential Star, or GWP*, to measure methane emissions. Initially developed to quantify the warming impact of various greenhouse gases, the scientists argue GWP* is misused by the livestock industry to dilute efforts in reducing methane emissions primarily from livestock.
Major emitters such as the United States, European Union, Brazil, and Argentina advocate for GWP* to alter climate targets, aiming for “temperature neutrality” rather than significant emission cuts. Scientists warn this approach permits the beef and dairy industries, key methane contributors, to persist in high emissions.
“The concern is that once one country adopts these targets, others may follow,” said Paul Behrens, an environmental scientist at the University of Oxford. “We need deep methane cuts to reduce near-term warming, but a ‘no additional warming’ target maintains high emission levels and negates our most effective cooling strategy.”
If Ireland adopts a “temperature neutrality” goal using GWP* in its 2031-2035 carbon budget, it could emit 9 million more tons of carbon dioxide equivalent, comparable to burning 20 million barrels of oil. New Zealand, a dairy giant, adopted a “no additional warming” target in 2025 using GWP*, weakening its methane reduction commitments.
The Intergovernmental Panel on Climate Change and Paris Agreement signatories use GWP 100 to measure cumulative emissions over 100 years relative to carbon dioxide. GWP* assesses the warming impact of emission rate changes over time, focusing on shorter-lived gases like methane, lasting around 10-12 years in the atmosphere.
Scientists, including Michael Mann and Drew Shindell, argue that using a baseline allows countries to overlook existing cattle impacts. “GWP* is misused for future temperature projections,” said Shindell, a climate scientist at Duke University. “For accountability, current emissions should be compared to historical levels.”
Methane concentrations in the atmosphere are about 2.5 times higher than pre-industrial levels, responsible for one-third of global warming.
“We have more cows now, and their methane emissions have significantly increased,” Shindell noted. “This contributes greatly to climate change, approximately half a degree by 2020.”
Scientists emphasize that GWP* favors countries with large herds, while developing nations with smaller herds are disadvantaged when increasing emissions from a lower baseline.
“It’s about equity,” Shindell said. “High emitters get rewarded. Countries with high methane emissions, like the U.S., can maintain them, disadvantaging less industrialized nations.”
Original Story at insideclimatenews.org